Master/slave circuits are not new and have been provided in terminal boxes into which the master can be plugged along with slave units so that the slaves are energized when the master is energized. These circuits have been quite sophisticated and, consequently, quite expensive, but the expense was justified since they were largely used in connection with some very sophisticated, costly equipment such as computers.
The object of this invention is to provide a low-cost master/slave circuit enabling use in conjunction with power tools in particular, although being suitable for a number of other uses as well.